Diagnostic Performance of CT for Occult Proximal Femoral Fractures: A Systematic Review and Meta-Analysis.

OBJECTIVE. The purpose of this study was to assess the diagnostic performance of CT for detection of occult proximal femoral fracture. MATERIALS AND METHODS. A systematic search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed for studies of the sensitivity and specificity of CT for detection of hip fracture. Two independent investigators extracted data and assessed the quality of each study using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). A qualitative systematic review and quantitative meta-analysis were performed. A Bayesian bivariate random effects meta-analysis model with integrated nested Laplace approximation was used to estimate sensitivity and specificity. RESULTS. Thirteen heterogeneously reported studies were assessed that included 1248 patients (496 with a hip fracture and 752 without) with MRI or clinical follow-up as the reference standard. There were 50 false-negative examinations. The summary estimate of sensitivity was 94% and of specificity was 100%. CONCLUSION. CT can be considered a reasonable choice when occult proximal femoral fracture is suspected clinically in patients for whom MRI is contraindicated or not readily available. However, for patients with ongoing clinical concern about hip fracture despite normal CT findings, MRI should be performed.

Detection of Bone Marrow Edema in Nondisplaced Hip Fractures: Utility of a Virtual Noncalcium Dual-Energy CT Application.

Purpose To quantify the sensitivity and specificity of dual-energy computed tomographic (CT) virtual noncalcium images in the detection of nondisplaced hip fractures and to assess whether obtaining these images as a complement to bone reconstructions alters sensitivity, specificity, or diagnostic confidence. Materials and Methods The clinical research ethics board approved chart review, and the requirement to obtain informed consent was waived. The authors retrospectively identified 118 patients who presented to a level 1 trauma center emergency department and who underwent dual-energy CT for suspicion of a nondisplaced traumatic hip fracture. Clinical follow-up was the standard of reference. Three radiologists interpreted virtual noncalcium images for traumatic bone marrow edema. Bone reconstructions for the same cases were interpreted alone and then with virtual noncalcium images. Diagnostic confidence was rated on a scale of 1 to 10. McNemar, Fleiss κ, and Wilcoxon signed-rank tests were used for statistical analysis. Results Twenty-two patients had nondisplaced hip fractures and 96 did not have hip fractures. Sensitivity with virtual noncalcium images was 77% and 91% (17 and 20 of 22 patients), and specificity was 92%-99% (89-95 of 96 patients). Sensitivity increased by 4%-5% over that with bone reconstruction images alone for two of the three readers when both bone reconstruction and virtual noncalcium images were used. Specificity remained unchanged (99% and 100%). Diagnostic confidence in the exclusion of fracture was improved with combined bone reconstruction and virtual noncalcium images (median score: 10, 9, and 10 for readers 1, 2, and 3, respectively) compared with bone reconstruction images alone (median score: 9, 8, and 9). Conclusion When used as a supplement to standard bone reconstructions, dual-energy CT virtual noncalcium images increased sensitivity for the detection of nondisplaced traumatic hip fractures and improved diagnostic confidence in the exclusion of these fractures. © RSNA, 2017 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on March 17, 2017.